Wave-meter.



P. W'. MIDGLBY.

Patented Feb.27,1912,

2 SHEETS-SHEET `1.

, wireless transmission currnn sr "Pres earner ernten EEEDEEICK w. MIDGLEY, 0E JERSEY crrY. NEW JERSEY, Asseivon 'ro JOHN EIRTH,

' or NEW YORK, N. Y.

WAVE-METER.

To all whom it may concern Be it known that I, Fiznoemon lV. Mine- LEY, a' citizen of the United States, residing in Jersey City, county ot' Hudson, and State ot New Jersey, have invented certain new and useful Improvements in lave-Meters, ot which the :following is a specication.

My invention relatesto wave meters tor .measuring the lengths (or frequencies) ot elect-ric waves, particularly of high frequency oscillations,- either sustained or in trains, such, for example, of wireless telegraphy and telephony, or

generally.

My invention resides in a wave meter which is compact and selt-contained, involving an adjustable condenser and an adjustable inductance, the' inductance coil surrounding the condenser. The inductance is provided in sections, with means for cutting in or out such sections. y

My invention resides also in the mode oi' connection, in a wave meter, ot' the detector or wave-responsive device in such manner that a minimum amount of energy is delivered to-or consumed. in the detector o r assed through the detector, whereby the oscillating circuit is very persistent, and, therefore, the resulting tuning is very sharp and accurate. Y

My invention resides in the Jfeatures hereinafter described and pointed out in the claims. l

For an illustration ot one of the forms my invention may take, reference is to be ha to the accompanying drawings, in which:

Figure 1 is a top plan view of a wave meter involving my invention. Fig. 2 is a sectional view on the line A-A ot' Fig. 1, some parts being shown in elevation. Fig. 8 is an interior plan view. Fig. 4 is a diagrammatic view representing the circuit arrangements.

The box 1, preferably Aof wood or other insulating material and having the bottom 2, is adapted to inclose and contain the inductance and condenser elements, and accessories,l of the wave meter. The condenser and inductance elements are supported upon the box cover 8 which is screwed on the top of the box 1. Supported by brackets 4 secured to the under side of the cover 3 is the cylinder or frame 5 of rubber or other suitable insulating material, upon which is wound the wire helix 6, preferably of cop- Speoication of Letters Patent. Application mea rebruary a5, 1911.

as used in the arts- Patented Feb. 27, 1912.

Serial No. 610,757. y

per or other low resistance material, the resistance ot the wire being made very low, by using wire of relatively great cross section. By rods 7 depending from the cover 3 and supporting at their lower ends the spider 8, are held the stationaryfconduct-ing plates 9 of the adjustable condenser These plates 9 are all electrically connected together and t'orm one armature of the condenser K. The other armature vof the condenser K comprises the conducting plates 1() all electrical-ly connected together and insulated from the plates 9, and supported by the member 11 which is rotatable about a vertical axis having a lower bearing in the spider 8 at 12 and a bearing at 13 in the cover 3. Outside the cover 3 and secured to the member 11 is the handle 11 carrying the pointer 15 adapted to sweep over the graduated scale S. The pointer 15 is enlarged at its outer end to form the opening lacross which extends theradially disposed niember 17, which is the indicating portion or inember of the pointer 15 and which sweeps over the scale S and tacilitatesthe reading of the scale directly beneath 'the member 17, the scale being visible through the opening 16. As the handle 111 is turned, the plates 10 are moved in interleaving relation with respect to the plates 9, air intervening between the plates of the two armatures of the condenser, such air 'forming the condenser dielectric. The plates S) are substantially se1nicircular in extent as are also the` plates 10, so that when the plates 10 do not interleave with the plates 9, the condenser has its minimum capacity, and may be varied through all values to maximum capacity which is reached when the plates 10 are wholly disposed between the plates 9.

Upon the cover 3 are disposed the binding posts 18 and 19, of which 18 is electrically denser K. A wire or plate 20 may electrically connect the binding posts 18 and 19.

The binding post 19 is electrically connected with the flexible conducting cord 21 on the 'under side of the cover which extends up through the hole 22 in the cover 8, and terminates at its outer end in the conducting plug 23, adapted to be inserted in any one of plug holes 24, 25, 26. 27, or 28 in the conducting plates or blocks 29, 30, 31, 32, or 33, respectively.

The blocks or plates 30, 31, 32, or 33 have connected with one armature of the con-- mg post 4G and to the bracket -l-'T formingl one terminal of a wa veresp ms1ve device or detector lV, 'comprising the upper elementI 48 and lower element Iif), the lower clement fit) being electrically connected to binding postl 50. The terminals of a telephone or other signal translating instrument 'l` are eoimected to the binding All these connections are more readfly understood from the diagram ot F ig. et. Here it. will be. seen that the inductance o coinprises, for example, ltive .(5) sections 5l,

53, 5t, and

lt willbe noted that the detector or wavei responsive device XV, which may be a silicon, perilion, earhorundum, or any other suitable detector, is not included either in shunt or in series with the oscillatingcircuit conn prisingl the adjustable condenser'K and the inductanee; -but that only one terminal of the detector lV is in electrical communication with the oscillating circuit. the other terminal of the detector being free or unconnected, so far as the oscillating circuit is concerned, and that the telephone or other instrument T is connected to the terminals of the'detector iV.

As shown in Fig. at, switches 8G and 3T are closed and the plug Q3 is inserted in the hole 2G of the plate orblock ft forming one terminal ot tht` induetance section The result is that there are included iu series with the condenser K the three imluctancc sections 51, 59. and 53. And by having switches 3l and 35 open, the induetanee sections 5l and 55 are entirely isolated, so that they in no practical way affectthe oscillating circuit. ,Blv this arrangement, it obvious that from one to tive sections of inductance may be included in the oscillating circuit at will by suitably placing the plug Q3 and by closing suitable switches and opening thev others, as cireumstai'lces may require, these sectionsot' inductauce giving the wave mete' a wide range.

In operation, the instrument is placed either within the| inductive, conductive, or radiant influence ot' the high frequency oscillations whose length or frequency is to be measured. there the oscillations are quite powerful, and the source of them near at hand, the instrun'lentneed o nly be held near the circuit which produces lthe oscillations,

posts it) and 50.-

relance and there will, accordingly, occur inthe oscillating circuit of the wave meter oscillations of .like frequency. Then, the amount of iinltuftanee in the circuit is adjusted by steps, as above ttt-scribed, and the capacity of the. condenser li gradually varied by tlnning the handle l-l until the sound or indication in the instrument 'il a maxinnnu. 'llhe operator then reads the scale indication immediately below the member 'ti' of the pointer l5 for that position of adjustment of the condenser K. I'this scale may be calibrated either in degrees, so that from a curve sheet accompanying the instrun'ient the frequency or wave length may be read, or the scale S may be directly calibrated in frequency or wave length. In such case, the scale S may comprise, in fact, several scales7 to accord with the different.'numbers of inductance sections included in the oscillating circuit. *lither the conductor 20 or conductor 45 may be'removed from the associated binding posts and conductors led outwardly in a loop from such binding posts tothe region of influence of the oscillating circuit whose oscillations are to be measured or in place of either conductor 20 or conductor it-5, there may be connected a miliammeter or other measuring instrument or device as occasion may require.' v

As above stated, the detector or wave-responsive device \V is'not connected in the oscillating circuit either in shunt or in series, but has only one unipolar connection with the oscillating circuit.` The result is. that the detector does not to any appreciable dcgree atl'ect the pcrsistency of the oscillating circuit of the wave meter, and in the arrangement shown derives from the oscillating circuit a minimum of energy, leaving the oscillating circuit persistent and capable of sharpest and most` accurate resonance or tuning, and, therefore, most accurate measurement of wave length or frequency. The linksor conductors Q0 and 45 may also be removed for quickly disconnecting the coudenser and the inductance from each other.

The hcreinl'iefore described construction results in a compact wave meter which, considering its range, is small and light, and does away with exterior interchangeable or removable inductance windings or coils, which in use in prior devices render the same large and unwieldy.

Vhat I claim is:

l. A wave meter comprising a casing, a y

closing wall therefor, a condenser and an inductance both supported upon said closing wall and removable therewith from said casing, said condenser comprising stationary and movable armatures, each armature comprising separated parallel plates, and a rotatable shaft carrying 'said movable armaturefor rotating the plates thereof to position between Ithe plates of said stationary member, and switching mechanism compris-' said inductance comprising a coil armature,

extending entirely having convolutions around said condenser, ductance ooil convolutions and of said rotatable shaft being substantially coincident.

2. -In a wave meter, a supporting member, a condenser supported upon said supporting member and comprising stationary and movable armatures, each armature comprising separated parallel plates, a rotatable shaft supporting said movable armaturev for rotating the plates thereof to position between thepla`tes of said stationary armature, an

inductance coil carriedby said supporting' member and extending entirely around said condenser, the axis of said inductance' lcoil rbeing substantially parallel with the axis 'of said condenser, said condenser and inductance coil connected in series with each other, said inductance coil divided into sections, terminals for each section upon said supporting ing a movable plug and switch blades for including in circuit one or more sections of said inductance coil `and -for isolating the` other sect-ions.

3'. In a wave meter, a supporting member, a condenser supportedupon said supporting member and comprising stationary and movable armatures, each armature comprising separated parallel plates, a rotatable shaft supporting said tating the plates the plates of said stationary armature, an inductance coil carried by said supporting member and extending entirely around said condenser, the'axis of said inductance coil l being substantially parallel with-the axis of said condenser, a flexible conducting cord connected in series with said inductance coil and said condenser, a plug onvsaid flexible` cord, said inductance coil divided into' sections having terminals on said supporting member, 'said plug adapted to engage with said terminals, and switch blades cooperating with said terminals, whereby sections of said .inductance coil may be con- 'A nected in. circuit and the other sections isolated.

4. A. wave meter comprising a condenser and inductance forming an oscillating circuit, and a self-restoring detector having unipolar connection with said oscillating circuit. l

5.4 A wave meter comprising a condenser and inductance forming an oscillating circuit, a self-restoring detector` having unithe axis of said inhaving fixed and movable armatures,

-means for including one or movable armature for rothereof to position between l polar 'connection with said .oscillating circuit, and a signal having its terminals connected to nals of said detector device.

6. A wave meter comprising a condenser ported within said casing Aupon said cover,.

said inductance divided into sections, and

switches upon said cover for including in.

said inductance sections.

8.In a wave meter, a casing, a cover therefor, a condenser and inductance sup a plun circuit with said condenser one or more,of

translating instrument l a supporting member, said ported'within said casing uponsaid cover,

said inductance dividedinto sections, and switches upon said cover for including in circuitv with said-condenser 'one or more of i said induct-ance sections and for isolating the other'sections-of inductance:4

9. In a wave vmeter, a casing, aV cover therefor,

dersupported upon said cover withinsaid casing and inclosing and surroundingsaid condenser, and an inductance wound upon said frame or, cylinder".

v10. In a wave meter', a. casing, al cover therefor, aV condenser supported upon. said cover within said casing, a frame or cylinder supported upon said casingv 'and inclosing and` surrounding said condenser, andan inductance wound upon said frame or cylinder, said condenser comprising the axis vrotation of said' rotatable armature being substantiallycoincident with the axis of said frame or cylinder.

In testimony Ywhereof I have hereunto` a condenser supported .upon said.4 lcover within said casing,`a lframe or cylincover withinl said stationary and.l rotatable armatures,

affixed Amy signature. Ain the presence of the .l

two subscribing witnesses.`

Witnesses: l

CHAnLEs' G. RENNAR, -ANNA E. STEINBOCK.

runnin-nouw. MIDGLEY. 

